"I have never suggested that Sen. McCain picks his positions on national security based on politics or personal ambition. I have not suggested it, because I believe that he genuinely wants to serve America's national interest. Now it's time for him to acknowledge that I want to do the same," Obama declared in a roughly 30-minute speech to an audience of 3,000 here.

"Let me be clear: I will let no one question my love of this country. I love America, so do you, and so does John McCain. When I look out at this audience, I see people of different political views. You are Democrats and Republicans and independents. But you all served together, and fought together, and bled together under the same proud flag. You did not serve a Red America or a Blue America -- you served the United States of America.

Obama drew applause when he said the candidates should instead focus on the issues. "Let's have a serious debate, and let's debate our disagreements on the merits of policy -- not on personal attacks," he said. "No matter how heated it gets or what kind of campaign he chooses to run, I will honor Sen. McCain's service, just like I honor the service of every veteran in this room, and every American who has worn the uniform of the United States of America."

In his speech, Obama laid out the case for his ability to deal effectively with world affairs, providing a point-by-point rebuttal to his rival's argument that he had more ambition than judgment. He also touched on his plans for veterans in the areas of education and health care.

Obama said McCain had offered a "typical laundry list of political attacks."

"He said that I have changed my position on Iraq when I have not. He said that I am for a path of 'retreat and failure.' And he declared, that 'Behind all of these claims and positions by Sen. Obama lies the ambition to be president' -- suggesting, as he has many times before, that I put personal ambition before my country," Obama said. "Now that is John McCain's prerogative. He can run that kind of campaign, and -- frankly -- that's how political campaigns have been run in recent years. But I believe the American people are better than that. I believe that this defining moment demands something more of us."

The presumptive Democratic nominee argued he had shown better judgment than McCain when it came to the war in Iraq, which he opposed, said the Arizona senator had followed his lead on calling for more troops for Afghanistan. Obama also criticized McCain for what he characterized as his unwillingness to track down Osama bin Laden in Pakistan.

"A year ago, I said that we must take action against bin Laden and his lieutenants if we have them in our sights and Pakistan cannot or will not act," he said. "Sen. McCain criticized me and claimed that I was for 'bombing our ally.' So for all of his talk about following Osama bin Laden to the Gates of Hell, Sen. McCain refused to join my call to take out bin Laden across the Afghan border. Instead, he spent years backing a dictator in Pakistan who failed to serve the interests of his own people."

The McCain campaign sent out a statement saying Obama doubted McCain's commitment to finding bin Laden, simply because he had not "projected an outspoken intention to bomb territories" in an ally. "Unlike Barack Obama, John McCain doesn't have to compensate for a lack of credibility on the international stage with inflammatory and public threats against American allies," said spokesman Tucker Bounds. "The American people know that John McCain will hunt down terrorists wherever they are, and have a choice between strength and experience versus Barack Obama's rhetoric and theatrics."

In his remarks, Obama also argued that the crisis in Georgia underscored the need for an engaged America. But he said the United States had been distracted, its resources overstretched and its alliances frayed.

"For months, I have called for active international engagement to resolve the disputes over South Ossetia and Abkhazia. I made it crystal clear before, at the beginning of, and during this conflict that Georgia's territorial integrity must be respected, and that Georgia should be integrated into transatlantic institutions," he said. "I have condemned Russian aggression, and today I reiterate my demand that Russia abide by the cease-fire. Russia must know that its actions will have consequences."

He added that he was joining Sen. Joe Biden in calling for an additional $1 billion in reconstruction assistance to the country. Biden, whose name has been mentioned on the short list of possible vice presidential candidates, traveled to Georgia over the weekend.

Furthermore, Obama hit McCain for opposing a new GI bill and criticized what he suggested was an effort to privatize the VA, after McCain spoke yesterday about the Veterans' Care Access Card he has proposed.

"We need to get rid of means-testing. Every veteran should be allowed into the VA system. My opponent takes a different view," he said. "He wants to ration care so the VA only serves combat injuries, while everyone else gets an insurance card. While the VA needs some real reform to better serve those who have worn the uniform, privatization is just not the answer. We cannot risk our veterans' health care by turning the VA into just another health insurer. We need to make sure the VA is strong enough to treat every veteran who depends on it."

McCain said Monday that the card was intended for any veteran with an "illness or injury incurred during their military service, and by those with low incomes" and called it an expansion of the VA -- not privatization.